Seat rail device

Abstract

A seat rail device provided with an upper rail 1 engaged with and mounted onto a lower rail 2 such that an upper bottom wall section 11 is located above a lower bottom wall section 21 and also such that an upper sloped wall section 16 is located within a lower groove 26 surrounded by a lower wall section 23 , a lower top plate section 25 , and a lower downwardly extending section 27 ; a roller 31 provided and rollably supported between the lower bottom wall section 21 and the upper bottom wall section 11 ; an upper ball-shaped rolling body 33 provided and rollably supported in an upper in-groove space 26 a partitioned and defined in the lower groove 26 by the upper sloped wall section 16 ; and a lower ball-shaped rolling body 35 provided and rollably supported in a lower in-groove space 26 b.

The invention claimed is: 
     
       1. A seat rail device wherein an upper rail for supporting a seat is provided on a lower rail, rolling bodies are provided between the lower and upper rails, and the upper rail is movable along the lower rail via the rolling bodies,
 wherein the lower rail includes, with respect to a cross-section perpendicular to the longitudinal direction of the lower rail, a lower bottom wall section that forms a rail bottom, a lower wall section that extends upward from an outer edge of the lower bottom wall section, a lower top plate section that extends from an upper edge of the lower wall section toward an inner side above the lower bottom wall section, and a lower downwardly extending section that extends downward from an edge of the lower top plate section, 
 wherein the upper rail includes, with respect to a cross-section perpendicular to the longitudinal direction of the upper rail, an upper upright wall section that includes a seat supporting portion formed at an upper portion thereof, an upper bottom wall section that extends toward an outer side from a lower edge of the upper upright wall section, an upper wall section that extends upward from an edge of the upper bottom wall section, and an upper sloped wall section that extends obliquely upward from an upper edge of the upper wall section, 
 wherein the upper rail is provided above the lower rail so that the upper bottom wall section is positioned above the lower bottom wall section and the upper sloped wall section is positioned in a lower groove having a lower opening surrounded by the lower wall section, the lower top plate section, and the lower downwardly extending section, 
 wherein an inter-bottom-wall rolling body is provided between the upper and lower bottom wall sections and is rollably supported so as to support the upper bottom wall section above the lower bottom wall section, an upper ball-shaped rolling body is provided and rollably supported in an upper in-groove space partitioned and defined by the upper sloped wall section in the lower groove, and a lower ball-shaped rolling body is provided and rollably supported in a lower in-groove space so that the upper sloped wall section is supported from both sides in the lower groove, 
 wherein the upper sloped wall section, which extends obliquely upward from the upper edge of the upper wall section, extends in a direction toward the lower downwardly extending section and away from the lower wall section, and 
 wherein the upper in-groove space is defined as a space surrounded by the lower wall section, the lower top plate section, and the upper sloped wall section, and the lower groove space is defined as a space surrounded by the lower downwardly extending section and the upper sloped wall section. 
 
     
     
       2. The seat rail device according to  claim 1 ,
 wherein a recessed groove that is recessed toward an upper surface of the upper sloped wall section is formed on a lower surface of the upper sloped wall section and/or a recessed groove that is recessed toward an outer surface of the lower downwardly extending section is formed on an inner surface of the lower downwardly extending section, so that the lower ball-shaped rolling body is received in the formed recessed groove and is rollably supported without falling out. 
 
     
     
       3. The seat rail device according to  claim 1 , wherein the inter-bottom-wall rolling body is a roller-shaped rolling body. 
     
     
       4. The seat rail device according to  claim 1 , wherein the upper rail further includes a second upper bottom wall section that extends toward the inner side from the lower edge of the upper upright wall section, and a second upper extension section that extends upward from an edge of the second upper bottom wall section, and
 wherein the lower rail further includes a lower locking section that is folded so as to surround the second upper extension section and extends from the inner edge of the lower bottom wall section while maintaining a predetermined gap between said lower locking section and the second upper bottom wall section and the second upper extension section. 
 
     
     
       5. The seat rail device according to  claim 4 ,
 wherein the second upper extension section extends obliquely upward from the edge of the second upper bottom wall section so as to form an obtuse angle. 
 
     
     
       6. The seat rail device according to  claim 4 ,
 wherein a height of the lower locking section, which is folded so as to surround the second upper extension section, is lower than that of a lower edge of the lower downwardly extending section. 
 
     
     
       7. The seat rail device according to  claim 4 , wherein the upper upright wall section, the upper bottom wall section, the upper wall section, and the upper sloped wall section are formed on a first plate, and
 wherein the second upper bottom wall section and the second upper extension section are formed on a second plate, and wherein the second plate further includes a second upper upright wall section which extends along the upper upright wall section of the first plate. 
 
     
     
       8. The seat rail device according to  claim 1 , further comprising:
 a lock mechanism that restricts the movement of the upper and lower rails, wherein the lock mechanism includes a lock member that includes engagement protruding portions and is supported on the inner surface of the upper upright wall section of the upper rail, proximal through-holes that are formed in the upper upright wall section of the upper rail, and lock-engagement sections that are formed at the lower downwardly extending section of the lower rail, 
 wherein the upper rail is locked in a movement prohibition state when the engagement protruding portions of the lock member are engaged with the lock-engagement sections while being inserted into the proximal through-holes. 
 
     
     
       9. The seat rail device according to  claim 8 , wherein the lower rail comprises an inner wall section on the inside of the lower bottom wall section, wherein a height of the inner wall section is set to a height so that the lock member is mounted on the upper rail above the inner wall section, and
 wherein the height of the inner wall section is set lower than that of the lower end of the lower downwardly extending section. 
 
     
     
       10. The seat rail device according to  claim 9 ,
 wherein the lower rail further includes a lower locking section that includes a second top wall section extending toward the outer side from an end edge of the inner wall section so as to have a height lower than the lower end of the lower downwardly extending section, and a second downwardly extending section extending toward the lower bottom wall section from an end edge of the second top wall section, 
 wherein the upper rail includes the upper upright wall section provided on the outer side and the second upper upright wall section provided on the inner side, wherein the upper upright wall section and the second upper upright wall section are parallel to each other, and wherein the second upper bottom wall section extends from the second upper upright wall section that is formed on the inner side, 
 wherein the upper rail further includes a second upper bottom wall section and a second upper extension section which extends upward from an end edge of the second upper bottom wall section, wherein an end edge of said second upper extension section is positioned in the lower locking section, and 
 wherein the lock member is supported on the inner surface of the second upper upright wall section. 
 
     
     
       11. The seat rail device according to  claim 8 ,
 wherein the lock mechanism further includes distal through-holes formed in the upper wall section, and wherein the upper rail is locked in a movement prohibition state when the engagement protruding portions of the lock member are engaged with the lock-engagement sections and are inserted into the distal through-holes while being inserted into the proximal through-holes. 
 
     
     
       12. The seat rail device according to  claim 8 ,
 wherein the lock member comprises a spring formed by bending a linear elastic body in a corrugated shape so that the engagement protruding portions are formed, both ends of the lock member are supported on a surface of the upper upright wall section, 
 wherein the lock-engagement sections are formed by cutting the lower end edge of the lower downwardly extending section in a corrugated shape, 
 wherein, when a middle portion of the spring is pressed and moved down, the engagement protruding portions are disengaged from the lock-engagement sections and a locked state thereof is released, and when the middle portion of the spring is not pressed down, the spring returns due to a spring force and the engagement protruding portions are engaged with the lock-engagement sections so as to enter into a locked state. 
 
     
     
       13. The seat rail device according to  claim 12 ,
 wherein the proximal through-holes formed at the upper upright wall section and the distal through-holes formed at the upper wall section include lock pieces that extend downward from the inner surfaces of upper wall portions of the proximal through-holes and the distal through-holes in to the through-holes. 
 
     
     
       14. The seat rail device according to  claim 4 ,
 wherein the width of the upper bottom wall section of the upper rail is larger than that of the second upper bottom wall section.